This invention relates to improvement in a bill validator used for validating bills, gift coupons and the like (hereinafter referred to as "a bill" ) in a vending machine or the like machine handling money, coupons or the like.
Various bill validators have been proposed in the past and these bill validators have a general structure according to which, as shown in FIG. 6, a bill forwarded by bill forwarding means is pressed in a direction normal to the surface of the bill to store it between a bill support 50 and a bill stopping rib (or channel member) 51 (e.g., Japanese Preliminary Patent Publication No. 60-77287 and corresponding U.S. patent application Ser. No. 656,585 now U.S. Pat. No. 4,678,072).
In such prior art bill validators, the bill support 50 is always pressed against the rib 51 by force of a spring 52. As the number of received bills increases, therefore, the counterpressure of the spring increases and a bill pressing device 53 requires a pressing force which will overcome the counterpressure of the spring. On the other hand, the force of the spring 52 must be such that it will exercise a sufficient pressing force even when there is no bill to be received, i.e., when the spring 52 is stretched to the extremity. For this reason, the counterpressure of the spring 52 is of a relatively large value when the number of bills received is large. This necessitates provision of a motor section (motor M2) of the bill pressing device 53 having a large torque equivalent to the counterpressure of the spring which is encountered at a maximum number of received bills. Further, if it is desired to increase the maximum number of bills to be received, it is not sufficient to increase the capacity of a bill box but a motor of a larger size must be employed as the motor M2 for increasing the required torque. Besides, since in this type of device the bill is moved in sliding movement along the inner surface (particularly the bottom surface) of the bill box every time the bill is received, the bill pressing device 53 is required to have a pressing force overcoming the friction caused by this sliding movement in addition to the pressing force overcoming the force of the spring. This friction increases as the number of received bills increases so that the pressing force of the bill pressing member 53 must increase. For these reasons, the prior art bill validator has the disadvantage that the motor section and structure for pressing bills tend to become undesirably large. Moreover, since there is limitation on the power, mere increase in the capacity of the bill box is not sufficient for receiving more bills. Furthermore, the friction due to the sliding movement of the bill sometimes damages the bill (particularly in the lower end portion thereof). This sometimes poses a serious problem because the peripheral portion of the bill becomes rigid due to friction caused by frequent sliding movement of the bill with a result that the bill becomes unusable in circulation.